Compounding is the process of mixing multiple components including polymers, colorants, additives and fillers. This is often done in an extruder, such as a twin screw extruder. Pelletizing is the process of chopping extruded material into small pellets for use in a later process. A masterbatch is a compounded batch of pellets which contains a high concentration of an additive or filler in a polymer. Pellets from a masterbatch would be re-compounded along with unfilled pellets to create a desired concentration of additive or filler.
Many manufacturing processes involving plastics incorporate the use of pellets. Pellets are typically fed into an extruder where they are melted and pressurized for subsequent processes. These manufacturing processes include extrusion, injection molding, and blow molding. Pellets can also be used in recycling processes. In recycling processes, the degree of crystallinity of the polymer may be important such as in recycling PET (Polyethylene terephthalate) plastic.
Nanostructured materials are generally regarded as materials having very small grain feature size, typically in the range of approximately 1-100 nanometers (10−9 meters). Metals, ceramics, polymeric and composite materials may be processed in a variety of ways to form nanosized features. These materials have the potential for wide ranging applications, including for example, industrial, biomedical, 3D printing and electronic applications. As a result, a great deal of study is ongoing to gain a better understanding of the characteristics of these materials.
Conventional extrusion formed products are limited to approximately twelve layers. Micro-layer extrusion processes can extend these limitations. Micro-layer extrusion processes that provide methods for obtaining small grain features is described in U.S. Pat. No. 7,690,908, (hereinafter the “908 patent”) and U.S. Patent Publication 2012/0189789 (hereinafter the “789 Publication”) both of which are commonly owned by the assignee of the instant application, the disclosures of which are incorporated herein by reference in their entirety. Further examples of extrusion technology are described in U.S. Pat. Nos. 6,669,458, 6,533,565 and 6,945,764, also commonly owned by the assignee of the instant application and the disclosures of which are incorporated herein by reference in their entirety.